$root:'../images/';
%cfx{
  *zoom:1;
  &:after{
    content:"."; display:block; clear:both; visibility:hidden; line-height:0; height:0;
  }
}
@mixin bg($img){
  background-image:url($root + $img);
  background-repeat:no-repeat;
}
@mixin wh($w,$h){
  width:$w+px;
  height:$h+px;
}
@mixin bp($x,$y){
  background-position:$x+px $y+px;
}